March 27, 2006

If you are looking for a dull, matte look, then plating brass directly on the steel hinges is fine. But if you want a bright look, plating first with nickel (or white bronze) and then with brass is the "standard" approach and probably the most economical because brass does not "level" enough to be brightly reflective directly on unbuffed steel.

An alternative would be nickel plating followed by a brass tinted electrophoretic lacquer, and this would eliminate the need for cyanide in the process. This has been done on a lot of "brass" lamps, but I don't personally know whether it will work with hinges; electrophoretic lacquer coatings are very thin, so there may be no bridging between moving parts but I don't know for sure.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

THANKS FOR YOUR INFORMATION REGARDING BRASS PLATING. CAN I GET THE SAME YELLOW FINISH BY ZINC YELLOW PASSIVATION. AS THIS IS MOST ECONOMICAL.

ASHUTOSH
PIANO HINGES - JALANDHAR CITY, PUNJAB, INDIA

They certainly can be zinc plated and yellow chromated, and a person who is not sophisticated in metal finishing may not object; but even the best yellow chromate doesn't really look much like brass to someone who is looking for luster. Letter 4206 addressed this same issue.

One issue I have as operator of this site is that in trying to help the thousands of homeowners and consumers who submit maintenance questions about metal finishes, they often don't know what a finish really is these days. I realize that "piano hinges" aren't used exclusively on pianos, but if an owner rubs the chromate off the hinges on their new piano by using brass polish, who is responsible? If you used yellow chromate to try to make the hinges look like brass, I think you are. Good luck.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ